Many industrial waste materials, such as radioactive wastes, chemically hazardous wastes, or toxic elemental wastes, present difficult disposal problems due to the hazard of the material and the intensely regulated nature of these materials. When halogens are contained within such waste material, the halogens create unique problems, which are not adequately addressed by conventional treatment methods.
Sources of halogen-containing waste include, not only processes that create halide salts or halogens-containing compounds, but also wastes contaminated by radioactive or other hazardous materials. A chloride salt purification process used to process plutonium in a weapons complex is one example of a process generating halogen-containing waste. That process generates large quantities of chloride-containing radioactive wastes. Halogen-containing plastics, used as components of radioactive or chemically hazardous wastes streams or equipment are another example of halogen-containing wastes. These also require treatment for such disposal.
Halogen-containing compounds are also used to create chemically resistant or fireproof manufactured goods which also present unique disposal problems. Examples include many plastics, such as Hypalon.RTM. plastic, a product of Dupont, Wilmington, Del., which are used to insulate electrical wire. Hypalon.RTM. plastic also contains valuable lead oxide that should be recovered both for recycling and to avoid long-term problems with the toxicity of the lead. In other cases, plastic within a waste material must be destroyed to recover copper and other valuable materials. Thus, a problem with many halogen-containing waste materials is that they were originally designed with great care not to burn or be damaged by chemicals. Though very desirable in a manufactured product, these properties cause difficulties in the treatment and disposal of such materials.
With their water solubility, another significant problem with many halogen-containing wastes and waste forms (e.g. salts) is leaching and groundwater contamination. If a high quality waste form is to be made, the halogens should be removed from the waste before or during conversion to a waste form used for disposal.